Implantable sphincter assistance device with tuned magnetic features

ABSTRACT

An implantable restriction device includes a plurality of beads and a plurality of links that join the beads together. The beads include a housing including a contact surface, a passageway extending through the hosing along an axis, and at least one magnet disposed around the passageway. Portions of the links are slidably disposed in corresponding passageways of the beads such that the beads are operable to transition between a constricted configuration and an expanded configuration. The contact surfaces of adjacent beads abut against each other in the constricted configuration. Adjacent magnets within adjacent beads generate an interactive magnetic field foxed on the abutting contact surfaces of adjacent beads.

BACKGROUND

In some instances, it may be desirable to place a medical implant withinor surrounding a biological lumen/passageway in order to improve orassist the function of, or otherwise affect, the biologicallumen/passageway. Examples of such biological lumens/passagewaysinclude, but are not limited to, the esophagus, a fallopian tube, aurethra, or a blood vessel. Some biological passages normally functionby expanding and contracting actively or passively to regulate the flowof solids, liquids, gasses, or a combination thereof. The ability of abiological passage to expand and contract may be compromised by defectsor disease. One merely illustrative example of a condition associatedwith decreased functionality of a body passage is Gastro EsophagealReflux Disease (“GERD”), which effects the esophagus.

A normal, heathy, esophagus is a muscular tube that carries food fromthe mouth, through the chest cavity and into the upper part of thestomach. A small-valved opening in the esophagus, called the loweresophageal sphincter (“LES”), regulates the passage of food from theesophagus into the stomach, as well as the passage of acidic fluids andfood from the stomach toward the esophagus. The LES may also regulatestomach intra-gastric pressures. A healthy LES may contain pressure ofgasses within the stomach at around 10 mm Hg greater than normalintragastrical pressure, thereby impeding acidic gases/fluids fromrefluxing from the stomach back into the esophagus. When functioningproperly, a pressure difference greater than 10 mm Hg may regulate whenthe LES opens to allow gasses to be vented from the stomach toward theesophagus.

If the LES relaxes, atrophies, or degrades for any reason, the LES maycease functioning properly. Therefore, the LES may fail to sufficientlycontain pressure of gasses within the stomach such that acidic contentsof the stomach may travel back into the esophagus, resulting in refluxsymptoms. Two primary components that control the LES are the intrinsicsmooth muscle of the distal esophagus wall and the skeletal muscle ofthe crural diaphragm or esophageal hiatus. A causation of esophagealreflux, which may be associated with GERD, is relaxation of one or bothof the smooth muscle of the distal esophagus wall or the hiataldiaphragm sphincter mechanisms. Chronic or excessive acid refluxexposure may cause esophageal damage. Conventionally, treatment for GERDmay involve either open or endoscopic surgical procedures. Someprocedures may include a fundoplication that mobilizes of the stomachrelative to the lower esophagus, or suturing a pleat of tissue betweenthe LES and the stomach to make the lower esophagus tighter.

Examples of devices and methods that have been developed to treatanatomical lumens by providing sphincter augmentation are described inU.S. Pat. No. 7,175,589, entitled “Methods and Devices for Luminal andSphincter Augmentation,” issued Feb. 13, 2007, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,695,427, entitled“Methods and Apparatus for Treating Body Tissue Sphincters and theLike,” issued Apr. 13, 2010, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 8,070,670, entitled “Methods and Devicesfor Luminal and Sphincter Augmentation,” issued Dec. 6, 2011, thedisclosure of which is incorporated by reference herein; and U.S. Pat.No. 8,734,475, entitled “Medical Implant with Floating Magnets,” issuedMay 27, 2014, the disclosure of which is incorporated by referenceherein.

While various kinds and types of instruments have been made and used totreat or otherwise engage anatomical lumens, it is believed that no oneprior to the inventors has made or used an invention as describedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a cross-sectional side view, taken along a coronal planeof the body, of a biological passage;

FIG. 2 depicts a cross-sectional isometric view, taken along a coronalplane of the body, of a human esophago-gastric junction;

FIG. 3 depicts a top plan view of an exemplary sphincter augmentationdevice;

FIG. 4 depicts a partial, cross-sectional view of a portion of thesphincter augmentation device of FIG. 3;

FIG. 5A depicts a top, cross-sectional view of the sphincteraugmentation device of FIG. 3 positioned about an LES, with thesphincter augmentation device in an open and expanded configuration;

FIG. 5B depicts a top, cross-sectional view of the sphincteraugmentation device of FIG. 3 positioned about the LES of FIG. 5A, withthe sphincter augmentation device in a closed and contractedconfiguration;

FIG. 6 depicts a perspective view of an alternative magnet that may bereadily incorporated into the sphincter augmentation device of FIG. 3;

FIG. 7 depicts a cross-sectional perspective view of the magnet of FIG.6;

FIG. 8 depicts a cross-sectional view of two magnets of FIG. 6 alignedwith opposite poles directed adjacent to one another;

FIG. 9 depicts a cross-sectional view of a pair of alternative beads,each containing an alternative magnet, that may be readily incorporatedinto the sphincter augmentation device of FIG. 3;

FIG. 10 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 9, further showing the distance between the center of contact ofthe pair of beads and the contact location the generated magnetic fieldsare trying to achieve;

FIG. 11 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 9, further showing the width of the stronger portion of thegenerated magnetic field;

FIG. 12 depicts a cross-sectional view of the alternative magnet of FIG.9

FIG. 13 depicts a cross-sectional view of the pair of beads of FIG. 9,each containing an alternative magnet, that may be readily incorporatedinto the sphincter augmentation device of FIG. 3;

FIG. 14 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 13, further showing the distance between the center of contactof the pair of beads and the contact location the generated magneticfields are trying to achieve;

FIG. 15 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 13, further showing the width of the stronger portion of thegenerated magnetic field;

FIG. 16 depicts a cross-sectional view of the alternative magnet of FIG.13;

FIG. 17 depicts a cross-sectional view of the pair of beads of FIG. 9,each containing an alternative magnet, that may be readily incorporatedinto the sphincter augmentation device of FIG. 3;

FIG. 18 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 17, further showing the distance between the center of contactof the pair of beads and the contact location the generated magneticfields are trying to achieve;

FIG. 19 depicts a cross-sectional view of the pair of beads and magnetsof FIG. 17, further showing the width of the stronger portion of thegenerated magnetic field;

FIG. 20 depicts a cross-sectional view of the alternative magnet of FIG.17;

FIG. 21 depicts a perspective view of an alternative bead that may bereadily incorporated into the sphincter augmentation device of FIG. 3;

FIG. 22 depicts a top plan view of the bead of FIG. 21, with selectedportions of a casing cut away to reveal internal structures;

FIG. 23 depicts a top cross-sectional view of alternative beads housingmagnets of FIG. 6 that may be readily incorporated into the sphincteraugmentation device of FIG. 3;

FIG. 24 depicts a top cross-sectional view of alternative beads housingmagnets of FIG. 6, and an alternative link, both of which may be readilyincorporated into the sphincter augmentation device of FIG. 3, where thebeads are in a contracted configuration;

FIG. 25 depicts a top cross-sectional view of the beads and link of FIG.24, where the beads are in an expanded configuration;

FIG. 26 depicts a top plan view of an alternative sphincter augmentationdevice is a contracted configuration, with selected portions cut awayfor further clarity;

FIG. 27 depicts a top plan view of the sphincter augmentation device ofFIG. 26, in a slightly expanded configuration, with selected portionscut away for further clarity;

FIG. 28 depicts a top plan view of the sphincter augmentation device ofFIG. 26, in a fully expanded configuration, with selected portions cutaway for further clarity;

FIG. 29 depicts a perspective view of an alternative pair of beads andmagnet assemblies that may be readily incorporated into the device ofFIG. 3 or 26, with selected portions cut away for further clarity;

FIG. 30 depicts a perspective view of the pair of beads of FIG. 29 withan alternative magnet assembly, with selected portions cut away forfurther clarity;

FIG. 31 depicts a front cross-sectional view of bead of FIG. 29 with analternative magnet assembly;

FIG. 32 depicts a top plan view of a device the includes a plurality ofbeads as shown in FIG. 31, where the device is exposed to an MRI uniformfield; and

FIG. 33 depicts a top plan view of the device of FIG. 3, where thedevice is exposed to an MRI uniform field.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

I. Overview of Exemplary Sphincter Augmentation Device

FIGS. 1-2 show selected portions of human anatomy, which includes anesophagus (2) extending from the mouth, through a hiatus (8) defined bya diaphragm (10), and into a stomach (4). Esophagus (2) also includes adistal esophagus (3) and an LES (6). LES (6) is located along distalesophagus (3) adjacent to the junction of esophagus (2) and stomach (4).The portion of LES (6) extending through hiatus (8) is supported bydiaphragm (10). When functioning properly, LES (6) is configured totransition between an occluded state and an opened state (as shown inFIG. 2). As best seen in FIG. 2, LES (6) includes a plurality of slingfibers (12). Sling fibers (12) are smooth muscle tissue that may helpregulate LES (6) transition between the occluded state and the openstate. Hiatus (8) of diaphragm (10) may also help LES (6) transitionbetween the occluded state and the open state.

A healthy LES (6) transitions between the occluded state and the openedstate to act as a valve. In other words, a healthy LES (6) maytransition from the occluded state to the opened state to allow solids,liquids, and/or gasses to selectively travel between esophagus (2) andstomach (4). For example, a healthy LES (6) may transition from theoccluded state to the opened state to permit a bolus of food to travelfrom esophagus (2) into stomach (4) during peristalsis; or to ventintra-gastric pressure from stomach (4) toward esophagus (2).Additionally, in the occluded state, a healthy LES (6) may preventdigesting food and acidic fluid from exiting stomach (4) back intoesophagus (2).

If LES (6) ceases functioning properly by prematurely relaxing, andthereby improperly transitioning esophagus (2) from the occluded stateto the opened state, undesirable consequences may occur. Examples ofsuch undesirable consequences may include acidic reflux from stomach (4)into esophagus (2), esophageal damage, inflamed or ulcerated mucosa,hiatal hernias, other GERD symptoms, or other undesirable consequencesas will be apparent to one having ordinary skill in the art in view ofthe teachings herein. Therefore, if an individual has an LES (6) thatprematurely relaxes, causing improper transitions from the occludedstate to the opened state, it may be desirable to insert an implantaround a malfunctioning LES (6) such that the implant and/or LES (6) mayproperly transition between the occluded state and the opened state.

FIGS. 3-5B show an exemplary sphincter augmentation device (20) that maybe used as an implant around a malfunctioning LES (6) to assist the LES(6) in transitioning between the occluded state and the opened state.Device (20) of this example comprises a plurality of beads (30) that arejoined together by a plurality of links (40). Each bead (30) comprises apair of housings (32, 34) that are securely fastened to each other. Byway of example only, housings (32, 34) may be formed of a non-ferrousmaterial (e.g., titanium, plastic, etc.). Each bead (30) furthercomprises a plurality of annular or toroidal rare-earth permanentmagnets (60) that are stacked next to each other within housings (32,34). In the present example, magnets (60) are completely sealed withinbeads (30). As best seen in FIG. 4, each bead (30) also defines achamber (36) that is configured to receive a portion of a respectivepair of links (40). Housing (32) defines an opening (33) at one end ofchamber (36); while housing (34) defines an opening (35) at the otherend of chamber (36).

Each link (40) of the present example comprises a wire (42) that ispre-bent to form an obtuse angle. The free end of each wire (42)terminates in a ball tip (44). Beads (30) are joined together by links(40) such that a first end portion of a link (40) is in one bead (30), asecond end portion of the same link (40) is in another bead (30), and anintermediate portion of the same link (40) is positioned between thosetwo beads (30). Chambers (36) of beads (30) are configured to freelyreceive ball tips (44) and adjacent regions of wires (42); whileopenings (33, 35) are configured to prevent ball tips (44) from exitingchambers (36). Openings (33, 35) are nevertheless sized to allow wire(42) to slide through openings (33, 35). Thus, links (40) and beads (30)are configured to allow beads (30) to slide along links (40) through arestricted range of motion.

As best seen in FIGS. 5A-5B, two beads (30) have opposing fastenerfeatures (50) that allow the ends of device (20) to be coupled togetherto form a loop. In the present example, fastener features (50) compriseeyelets. In some other versions, fastener features (50) comprisecomplementary clasp features. As another merely illustrative example,fastener features (50) may be configured and operable in accordance withone or more of the teachings of U.S. patent application Ser. No.15/664,665, entitled “Method for Assisting a Sphincter,” filed Jul. 31,2017, the disclosure of which is incorporated by reference herein. Othersuitable ways in which the ends of device (20) may be coupled togetherto form a loop will be apparent to those of ordinary skill in the art inview of the teachings herein. Those of ordinary skill in the art willalso recognize that it may be desirable to provide fastener features(50) that can be decoupled if it becomes necessary or otherwisewarranted to remove device (20) from the patient.

FIGS. 5A shows device (20) in an open, expanded state, with device (20)being positioned about LES (6). At this stage, the opening (7) definedby LES (6) is in a persistently open state (e.g., allowing the patientto undesirably experience GERD and/or other undesirable conditions),warranting the securement of device (20) about the LES (6). FIG. 5Bshows device (20) secured about the LES (6), with device (20) in aclosed, contracted state. Device (20) is secured closed via fastenerfeatures (50). Magnets (60) are oriented within beads (30) such thateach bead (30) will be magnetically attracted to the adjacent bead (30)in device (20). In other words, beads (30) are magnetically attracted toeach other to magnetically bias device (20) toward the contractedconfiguration shown in FIG. 5B.

With device (20) secured around the LES (6) and in the contractedconfiguration, device (20) deforms the LES (6) radially inwardly tosubstantially close the opening defined by the LES (6). In doing so,device (20) prevents the patient from experiencing GERD and/or otherundesirable conditions that may be associated with a persistently openopening (7) at the LES (6). While magnets (60) have a tesla value thatis high enough to substantially maintain opening (7) in a closed stateto the point of preventing GERD and/or other undesirable conditions thatmay be associated with a persistently open opening (7), the tesla valueof magnets (60) is low enough to allow LES (6) to expand radiallyoutwardly to accommodate passage of a bolus of food, etc. through theopening (7) of LES (6). To accommodate such expansion, beads (30) maysimply slide along links (40) to enlarge the effective diameter ofdevice (20) as the bolus passes. After the bolus passes, the magneticbias of magnets (60) will return device (20) to the contracted stateshown in FIG. 5B. Device (20) thus ultimately prevents GERD and/or otherundesirable conditions that may be associated with a persistently openopening (7); while still permitting the normal passage of food, etc.from the esophagus (2) to the stomach (4).

In addition to the foregoing, device (20) may be constructed andoperable in accordance with at least some of the teachings of U.S. Pat.No. 7,695,427, the disclosure of which is incorporated by referenceherein; and/or U.S. patent application Ser. No. 15/664,665, entitled“Method for Assisting a Sphincter,” filed Jul. 31, 2017, the disclosureof which is incorporated by reference herein.

II. Exemplary Sphincter Augmentation Devices with Tuned MagneticFeatures

As mentioned above, magnets (60) are oriented within beads (30) suchthat each bead (30) will be magnetically attracted to the adjacent bead(30) in device (20), thereby biasing device (20) toward the contractedstate during exemplary use, as shown in FIG. 5B. As also shown in FIG.5B, exterior portions to adjacent beads (30) are dimensioned to abutagainst each other in the contracted state, which may help define theoverall structure of device (20) in the contracted state. When device(20) is suitably coupled with LES (6), the tesla value between magnets(60) may be high enough to maintain opening (7) in a closed state to thepoint of preventing undesirable conditions that may be associated with apersistently open opening (7), but low enough such that beads (30) maymove radially outwardly relative to each other by sliding along links(40), thereby effectively expanding device (20) to accommodate passageof a bolus of food, etc. through opening (7) of LES (6). Therefore,device (20) may repeatably transition between the contracted state andan expanded state while suitably attached to LES (6).

When device (20) repeatably transitions between the contracted state andthe expanded state, it may be desirable to control the alignment ofbeads (30) relative to one another as device (20) transitions betweenthe expanded state and the contracted state, or when device (20)experiences other external forces. Additionally, it may be desirable tocontrol the forces device (20) imparts on LES (6) due to the magneticattraction between adjacent beads (30) while device (20) is in thecontracted state, the expanded state, and all other configurationstherebetween.

One manner to accurately control the alignment of beads (30) and theforces device (20) imparts on LES (6) as mentioned above may be to form,modify, or otherwise “tune” magnets (60) to control the magnetic fieldvectors generated by individual magnets (60) relative to respectiveand/or adjacent beads (30). Another manner to accurately control thealignment of beads (30) and the forces device (20) imparts on LES (6) asmentioned above may be to align, form, modify, or otherwise “tune”magnets (60) within adjacent beads (30) to control magnetic fieldvectors generated by the interaction of magnets (60) within adjacentbeads (30). Another manner to accurately control the alignment of beads(30) and the forces device (20) imparts on LES (6) as mentioned abovemay be to align or otherwise strategically orient the above-mentionedmagnetic field vectors in relation to the contact surfaces, or any othersuitable alignment features, of beads (30). It should be understood theterm “vector” is used to represent a quantity having a magnitude and adirection. Therefore, when refencing any type of change and/ordifference in a vector or a field of vectors, it should be understoodthis change and/or difference might be in magnitude and/or direction.The term “tune” may encompass any suitable means, as would be apparentto one having ordinary skill in the art in view of the teachings herein,to control (or otherwise dictate) the flux, magnitude, or direction of amagnetic field, and its corresponding vectors.

Strategically controlling magnitude and/or direction of magnetic fieldvectors generated by magnets (60) (i.e. “tuning”) may allow moreaccurate control of the shape of device (20) as device (20) transitionsbetween the expanded state and the contracted state. Additionally,controlling the direction and intensity of magnetic fields generated bymagnets (60) may allow more accurate control of radial forces impartedon LES (6) while device (20) is in the various states/configurationsdescribed above.

A. Exemplary Magnets and Beads with Features for Coupling MagneticFields with Geometric Features of Beads

FIGS. 6-7 show an alternative magnet (100) that may be readilyincorporated into beads (30) in replacement of magnets (60) describedabove. In some instances, an individual magnet (100) may be placedwithin bead (30) instead of the plurality of magnets (60) describedabove. In such instances, a north pole section (110) may be adjacent toone opening (33) of bead (30) while a south pole section (112) may beadjacent to the opposite opening (35) of bead (30). In other instances,a plurality of magnets (100) may be “stacked” together within bead (30)in an end-to-end fashion. In such an instant, the plurality of magnets(100) may be aligned such that north pole section (110) of one magnet(100) is adjacent to one opening (33), while south pole section (112) ofanother magnet (100) is adjacent to the opposite opening (35) of bead(30). Of course, in either instance, magnets within adjacent beads (30)may be aligned such in a north-south relationship such that adjacentbeads (30) are magnetically attracted to each other in accordance withthe description above.

Magnet (100) is generally annular in shape defining an opening (105)dimensioned to receive a portion of housing(s) (32, 34) defining chamber(36). Magnet (100) includes a first annular axially presented surface(102), a second annular axially presented surface (104), a radiallyoutwardly facing curved surface (106), and a radially inwardly facingcurved surface (108) defining opening (105). Magnet (100) is axiallymagnetized such that the direction of magnetism extends from secondannular axially presented surface (104) toward first annular axiallypresented surface (102). Therefore, magnet (100) is divided into northpole section (110) and south pole section (112) such that first annularaxially presented surface (102) is entirely north pole section (110) andsecond annular axially presented surface (104) is entirely south polesection (112). North pole section (110) and south pole section (112) areseparated by a neutral border (114) such that outer facing curvedsurface (106) and inner facing curved surface (108) possess both northpole sections (110) and south pole sections (112).

As shown in FIGS. 7-8, axially presented surfaces (102, 104) of northpole section (110) and south pole section (112), respectively, aresubstantially flat and planar and connect to both outer facing curvedsurface (106) and inner facing curved surface (108). Magnet (100)produces/attracts magnetic field vectors (118). As best seen in FIG. 7,when magnet (100) is isolated by itself (i.e. is a suitable distancefrom other magnetic fields), field vectors (118) extend away from northpole section (110) and are attracted toward south pole section (112). Asalso best seen in FIG. 7, some field vectors (118) bend due to themagnetic attraction between polar sections (110, 112). The specific bendof field vectors (118) may be defined by the geometric shape of magnet(100). In particular, field vectors (118) bend due to the relationshipand shape of north pole section (110) and south pole section (112).Therefore, field vectors (118) emitted from portions of north polesection (110) that are close to south pole section (112) tend to bendtoward south pole section (112) to form a closed loop; while fieldvectors (118) emitted from portions of north pole section (110) that arefurther way from south pole section (112) are influenced by a lesserextent, thereby weakening the respective bend of field vectors (118)and/or not closing a loop.

Magnet (100), when isolated by itself from other magnetic fields,includes a plurality of magnetic field boundaries (116, 117). Due to theshape of magnet (100), field vectors (118) bending toward a magneticfield boundary (116, 117) do not cross such magnetic field boundary(116, 117). In the current example, there is a linear, central magneticfield boundary (117) extending along the central axis of magnet (100);and a cylindrical magnetic field boundary (116) spaced a predeterminedradial distance from the central magnetic field boundary (117).

As shown in FIG. 8, if two magnets (100) are positioned adjacent to eachother such that first annular axially presented surface (102) of onemagnet (100) is directly adjacent to second annular axially presentedsurface (104) of a second magnet (100), the magnetic field vector (118)of each magnet (100) is altered by the presence of one another. Inparticular, the magnetic field vector (118), and its associated magneticflux, is strongest between first annular axially presented surface (102)of the first magnet (100) (the magnet (100) on the left), and secondannular axially presented surface (104) of the second magnet (100) (themagnet (100) on the right). The distance between surfaces (102, 104) ofmagnets (100) plays a role in the magnetic force that attracts the twomagnets (100) together. In some instances, such as when incorporatedwithin beads (30) of device (20), the direction of the strongestmagnetic field vectors (118) between directly adjacent annular axiallypresented surfaces (102, 104) maybe important as well. In the presentexample shown in FIG. 8, the strongest magnetic field vectors (118) areperpendicular to surfaces (102, 104). If magnets (100), as shown in FIG.8, are housed in separate, directly adjacent beads (30), it may bebeneficial to align the magnetic field vectors (118) such that asuitable amount of magnetic field vectors (118) suitably align withcontacts surfaces of beads (30).

FIGS. 12, 16, and 20 show various alternative magnets (160, 200, 240)that may be readily incorporated into device (20) in replacement ofmagnets (60, 100) described above. In particular, magnets (160, 200,240) may be coupled with alternative beads (150), which may also bereadily incorporated into device (20) in replacement of beads (30)described above. As will be described in greater detail below, magnets(160, 200, 240) are shaped, formed, or otherwise “tuned” to directrespective magnetic fields (188, 228, 268) into suitable alignment withcontact surfaces (158) of beads (150).

Beads (150) are substantially similar to beads (30) described above,with differences elaborated below. Each bead (150) includes a chamber(152), a pair of openings (154), which are substantially similar tochamber (36) and openings (33, 35) described above, respectively.Therefore, beads (150) are configured to slidably receive links (40) inorder to expand and contract relative to each other in accordance withthe description above. Each bead (150) includes a pair of contactsurfaces (158) dimensioned to abut against contact surfaces (158) ofadjacent beads (150) in the contracted state, similar to bead (30)described above. Additionally, each bead (150) defines a magnet chamber(156) dimensioned to house at least one magnet (160, 200, 240) in asimilar orientation which bead (30) houses magnets (60). Therefore,magnets (60) are oriented within beads (150) such that each bead (150)will be magnetically attracted to the adjacent bead (150) in device(20). In other words, beads (150) are magnetically attracted to eachother to magnetically bias device (20) toward the contractedconfiguration.

FIGS. 9-11 show an alternative magnet (160) readily incorporated intobeads (150), which are readily incorporated into device (20) describedabove. Similar to magnets (60, 100) described above, an individualmagnet (160) or a plurality of magnets (160) may be placed within bead(150) such that a north pole section (170) may be adjacent to oneopening (154) of bead (30) while a south pole section (172) may beadjacent to the opposite opening (154) of bead (30). Magnets (160)within adjacent beads (150) may be aligned in a north-south relationshipsuch that adjacent beads (150) are magnetically attracted to each otherin accordance with the description above.

As best seen in FIG. 12, magnet (160) is generally annular in shapedefining an opening (165) dimensioned to receive a portion of bead (150)defining chamber (152). Magnet (160) includes a first annular axiallypresented surface (162), a second annular axially presented surface(164), an outer facing curved surface (166), and an inner facing curvedsurface (168) defining opening (165); which may be substantially similarto first annular axially presented surface (102), second annular axiallypresented surface (104), outer facing curved surface (106), and innerfacing curved surface (108) defining opening (105), respectively, withdifferences elaborated below.

Therefore, magnet (160) is axially magnetized such that the direction ofmagnetism extends from second annular axially presented surface (164)toward first annular axially presented surface (162). Therefore, magnet(160) is divided into north pole section (170) and south pole section(172) such that first annular axially presented surface (162) isentirely north pole section (170) and second annular axially presentedsurface (164) is entirely south pole section (172). North pole section(170) and south pole section (172) are separated by a neutral border(174) such that outer facing curved surface (166) and inner facingcurved surface (168) possess both north pole sections (170) and southpole sections (172).

Axially presented surfaces (162, 164) of north pole section (170) andsouth pole section (172), respectively, are substantially flat andplanar. However, unlike axially presented surfaces (102, 104) describedabove, axially presented surfaces (162, 164) each terminate into arespective chamfered outer diameter (176) and radiused inner diameter(178). In particular, chamfered outer diameters (176) connect axiallypresented surfaces (162, 164) with outer facing curved surface (166).Likewise, radiused inner diameters (178) connect axially presentedsurfaces (162, 164) with inner facing curved surface (168).

As best seen in FIG. 9, axially presented surfaces (162, 164) incombination with chamfered outer diameters (176) and radiused innerdiameters (178) are suitably dimensioned to create a suitable magneticfield (188A, 188B, 188C) having a stronger portion of magnetic field(188A), an intermediary portion of magnetic field (188B), and a weakestportion of magnetic field (188C); where strongest portion of magneticfield (188A) and an intermediary magnetic field (188B) are suitablyaligned with resting contact surfaces (158) of adjacent beads (150). Inother words, the geometric profile of north pole sections (170) andsouth pole sections (172) of magnets (160) within adjacent beads (150)are configured to generate a focused magnetic field (188A, 188B) that issuitably aligned with resting contact surfaces for optimal operatingconditions when beads (150) are incorporated into device (20) that iscoupled with LES (6).

In some instances, at least a portion of magnetic fields (188A, 188B)are perpendicular with resting contact surfaces (158). Magnetic fields(188A, 188B) may have another suitable alignment relative to restingcontact surfaces (158) as would be apparent to one having ordinary skillin the art in view of the teachings herein. The geometry of axiallypresented surfaces (162, 164) in combination with chamfered outerdiameters (176) and radiused inner diameters (178) may be configured togenerate sections of magnetic fields (188A, 188B, 188C), that arealigned with contact surfaces (158), configured to promote stabilitybetween adjacent beads (150) in the contracted state. Likewise, thegeometry of axially presented surfaces (162, 164) in combination withchamfered outer diameters (176) and radiused inner diameters (178) maybe configured to generate sections of magnetic fields (188A, 188B,188C), that are aligned with contact surfaces (158), to promote beads(150) to impart suitable forces on LES (6) due to the magneticattraction between adjacent beads (150) while device (20) is in thecontracted state, the expanded state, and all other configurationstherebetween. It should be understood that due to the focused directionof magnetic field (188A, 188B, 188C) relative to resting contactsurfaces (158), the control of stability and imparted forces may bebetter controlled than by just designing device (20) around the distancebetween magnets (60) in adjacent beads (30).

FIG. 10 highlights a distance (180) between the physical center (184) ofcontact between contact surfaces (158) and the contact location (182)the magnetic fields (188A, 188B) are trying to achieve. FIG. 11highlights the width (194) of the strongest portion of a magnetic fieldwhen there is no chamfered outer diameter (176) and radiused innerdiameter (178), as compared to the width (195) of the strongest portionsof magnetic field (188A, 188B, 188C) when chamfered outer diameter (176)and radiused inner diameter (178) are present. As noticed, the width(195) of the strongest portions of magnetic field (188A, 188B, 188C) isnarrower and more precisely “tuned” as compared to the width (194) ofthe stronger position of a magnetic field without chamfered outerdiameter (176) and radiused inner diameter (178). This may provide moreaccurately placement of beads (150) in the contracted state.

In some instances, radiused inner dimeter (178) may have a dimension of0.005 inches while chamfered outer diameter (176) may have a dimensionof 0.015 inches. Of course, any other suitable dimension may beincorporated as would be apparent to one having ordinary skill in theart in view of the teachings herein. In other instances, inner diameter(178) portion may be chamfered, while outer diameter portion (176) maybe radiused. In other instances, both outer diameter (176) and innerdiameter (178) may be chamfered or radiused. Of course, outer diameter(176), inner diameter (178), and axially presented surfaces (162, 164)may have any suitable geometry as would be apparent to one havingordinary skill in the art in view of the teachings herein. For example,an axially presented surface (162, 164) may be convex, concave,undulating, step-like, zig-zag, etc.

FIGS. 13-15 show an alternative magnet (200) readily incorporated intobeads (150), which are readily incorporated into device (20) describedabove. Similar to magnets (60, 100, 160) described above, an individualmagnet (200) or a plurality of magnets (200) may be placed within bead(150) such that a north pole section (210) may be adjacent to oneopening (154) of bead (30) while a south pole section (212) may beadjacent to the opposite opening (154) of bead (30). Magnets (200)within adjacent beads (150) may be aligned in a north-south relationshipsuch that adjacent beads (150) are magnetically attracted to each otherin accordance with the description above.

As best seen in FIG. 16, magnet (200) is generally annular in shapedefining an opening (205) dimensioned to receive a portion of bead (150)defining chamber (152). Magnet (200) includes a first annular axiallypresented surface (202), a second annular axially presented surface(204), an outer facing curved surface (206), and an inner facing curvedsurface (208) defining opening (205); which may be substantially similarto first annular axially presented surface (102), second annular axiallypresented surface (104), outer facing curved surface (106), and innerfacing curved surface (108) defining opening (105), respectively, withdifferences elaborated below.

Therefore, magnet (200) is axially magnetized such that the direction ofmagnetism extends from second annular axially presented surface (204)toward first annular axially presented surface (202). Therefore, magnet(200) is divided into north pole section (210) and south pole section(212) such that first annular axially presented surface (202) isentirely north pole section (210) and second annular axially presentedsurface (204) is entirely south pole section (212). North pole section(210) and south pole section (212) are separated by a neutral border(214) such that outer facing curved surface (206) and inner facingcurved surface (208) possess both north pole sections (210) and southpole sections (212).

Axially presented surfaces (202, 204) of north pole section (210) andsouth pole section (212), respectively, are substantially flat andplanar. However, unlike axially presented surfaces (102, 104) describedabove, axially presented surfaces (202, 204) each terminate into arespective chamfered outer diameter (216) and chamfered inner diameter(218). In particular, chamfered outer diameters (216) connect axiallypresented surfaces (202, 204) with outer facing curved surface (206).Likewise, chamfered inner diameters (218) connect axially presentedsurfaces (202, 204) with inner facing curved surface (208).

As best seen in FIG. 13, axially presented surfaces (202, 204) incombination with chamfered outer diameters (216) and chamfered innerdiameters (218) are suitably dimensioned to create a suitable magneticfield (228A, 228B, 228C) having a stronger portion of magnetic field(228A), an intermediary portion of magnetic field (228B), and a weakestportion of magnetic field (228C); where strongest portion of magneticfield (228A) and an intermediary magnetic field (228B) are suitablyaligned with resting contact surfaces (158) of adjacent beads (150). Inother words, the geometric profile of north pole sections (210) andsouth pole sections (212) of magnets (200) within adjacent beads (150)are configured to generate a focused magnetic field (228A, 228B) that issuitably aligned with resting contact surfaces for optimal operatingconditions when beads (150) are incorporated into device (20) that iscoupled with LES (6).

In some instances, at least a portion of magnetic fields (228A, 228B)are perpendicular with resting contact surfaces (158). Magnetic fields(228A, 228B) may have another suitable alignment relative to restingcontact surfaces (158) as would be apparent to one having ordinary skillin the art in view of the teachings herein. The geometry of axiallypresented surfaces (202, 204) in combination with chamfered outerdiameters (216) and chamfered inner diameters (218) may be configured togenerate sections of magnetic fields (228A, 228B, 228C), that arealigned with contact surfaces (158), configured to promote stabilitybetween adjacent beads (150) in the contracted state. Likewise, thegeometry of axially presented surfaces (202, 204) in combination withchamfered outer diameters (216) and chamfered inner diameters (218) maybe configured to generate sections of magnetic fields (228A, 228B,228C), that are aligned with contact surfaces (158), to promote beads(150) to impart suitable forces on LES (6) due to the magneticattraction between adjacent beads (150) while device (20) is in thecontracted state, the expanded state, and all other configurationstherebetween. It should be understood that due to the focused directionof magnetic field (228A, 228B, 228C) relative to resting contactsurfaces (158), the control of stability and imparted forces may bebetter controlled than by just designing device (20) around the distancebetween magnets (60) in adjacent beads (30).

FIG. 14 highlights a distance (220) between the physical center (222) ofcontact between contact surfaces (158) and the contact location (224)the magnetic fields (228A, 228B) are trying to achieve. FIG. 15highlights the width (234) of the strongest portion of a magnetic fieldwhen there are no chamfered outer diameters (216) and chamfered innerdiameters (218), as compared to the width (235) of the strongestportions of magnetic field (228A, 228B, 228C) when chamfered outerdiameters (216) and chamfered inner diameters (218) are present. Asnoticed, the width (235) of the strongest portions of magnetic field(228A, 228B, 228C) is narrower and more precisely “tuned” as compared tothe width (234) of the stronger position of a magnetic field withoutchamfered outer diameters (216) and chamfered inner diameters (218).This may provide more accurately placement of beads (150) in thecontracted state.

In some instances, chamfered diameters (216, 218) may have a dimensionof 0.01 inches. Of course, any other suitable dimension may beincorporated as would be apparent to one having ordinary skill in theart in view of the teachings herein. In some instances, only innerdiameter (218) or outer dimeter (216) is chamfered, while the othersimply connects to the respective curved surface (206, 208).

FIGS. 17-19 show an alternative magnet (240) readily incorporated intobeads (150), which are readily incorporated into device (20) describedabove. Similar to magnets (60, 100, 160, 200) described above, anindividual magnet (240) or a plurality of magnets (240) may be placedwithin bead (150) such that a north pole section (250) may be adjacentto one opening (154) of bead (30) while a south pole section (252) maybe adjacent to the opposite opening (154) of bead (30). Magnets (240)within adjacent beads (150) may be aligned in a north-south relationshipsuch that adjacent beads (150) are magnetically attracted to each otherin accordance with the description above.

As best seen in FIG. 20, magnet (240) is generally annular in shapedefining an opening (245) dimensioned to receive a portion of bead (150)defining chamber (152). Magnet (240) includes a first annular axiallypresented surface (242), a second annular axially presented surface(244), an outer facing curved surface (246), and an inner facing curvedsurface (248) defining opening (245); which may be substantially similarto first annular axially presented surface (102), second annular axiallypresented surface (104), outer facing curved surface (106), and innerfacing curved surface (108) defining opening (105), respectively, withdifferences elaborated below.

Therefore, magnet (240) is axially magnetized such that the direction ofmagnetism extends from second annular axially presented surface (244)toward first annular axially presented surface (242). Therefore, magnet(240) is divided into north pole section (250) and south pole section(252) such that first annular axially presented surface (242) isentirely north pole section (250) and second annular axially presentedsurface (244) is entirely south pole section (252). North pole section(250) and south pole section (252) are separated by a neutral border(254) such that outer facing curved surface (246) and inner facingcurved surface (248) possess both north pole sections (250) and southpole sections (252).

Axially presented surfaces (242, 244) of north pole section (250) andsouth pole section (252), respectively, are substantially flat andplanar. However, unlike axially presented surfaces (102, 104) describedabove, axially presented surfaces (242, 244) each terminate into arespective radiused outer diameter (256) and radiused inner diameter(258). In particular, radiused outer diameters (256) connect axiallypresented surfaces (242, 244) with outer facing curved surface (246).Likewise, radiused inner diameters (258) connect axially presentedsurfaces (242, 244) with inner facing curved surface (248).

As best seen in FIG. 17, axially presented surfaces (242, 244) incombination with radiused outer diameters (256) and radiused innerdiameters (258) are suitably dimensioned to create a suitable magneticfield (268A, 268B, 268C) having a stronger portion of magnetic field(268A), an intermediary portion of magnetic field (268B), and a weakestportion of magnetic field (268C); where strongest portion of magneticfield (268A) and an intermediary magnetic field (268B) are suitablyaligned with resting contact surfaces (158) of adjacent beads (150). Inother words, the geometric profile of north pole sections (250) andsouth pole sections (252) of magnets (240) within adjacent beads (150)are configured to generate a focused magnetic field (268A, 268B) that issuitably aligned with resting contact surfaces for optimal operatingconditions when beads (150) are incorporated into device (20) that iscoupled with LES (6).

In some instances, at least a portion of magnetic fields (268A, 268B)are perpendicular with resting contact surfaces (158). Magnetic fields(268A, 268B) may have another suitable alignment relative to restingcontact surfaces (158) as would be apparent to one having ordinary skillin the art in view of the teachings herein. The geometry of axiallypresented surfaces (242, 244) in combination with radiused outerdiameters (256) and radiused inner diameters (258) may be configured togenerate sections of magnetic fields (268A, 268B, 268C), that arealigned with contact surfaces (158), configured to promote stabilitybetween adjacent beads (150) in the contracted state. Likewise, thegeometry of axially presented surfaces (242, 244) in combination withradiused outer diameters (256) and radiused inner diameters (258) may beconfigured to generate sections of magnetic fields (268A, 268B, 268C),that are aligned with contact surface (158), to promote beads (150) toimpart suitable forces on LES (6) due to the magnetic attraction betweenadjacent beads (150) while device (20) is in the contracted state, theexpanded state, and all other configurations therebetween. It should beunderstood that due to the focused direction of magnetic field (268A,268B, 268C) relative to resting contact surfaces (158), the control ofstability and imparted forces may be better controlled than by justdesigning device (20) around the distance between magnets (60) inadjacent beads (30).

FIG. 18 highlights a distance (260) between the physical center (264) ofcontact between contact surfaces (158) and the contact location (262)the magnetic fields (268A, 268B) are trying to achieve. FIG. 19highlights the width (274) of the strongest portion of a magnetic fieldwhen there are no radiused outer diameters (256) and radiused innerdiameters (258), as compared to the width (275) of the strongestportions of magnetic field (268A, 268B, 268C) when radiused outerdiameters (256) and radiused inner diameters (258) are present. Asnoticed, the width (275) of the strongest portions of magnetic field(268A, 268B, 268C) is narrower and more precisely “tuned” as compared tothe width (274) of the stronger position of a magnetic field withoutradiused outer diameters (256) and radiused inner diameters (258). Thismay provide more accurately placement of beads (150) in the contractedstate.

In some instances, radiused diameters (256, 258) may have a dimension of0.005 inches. Of course, any other suitable dimension may beincorporated as would be apparent to one having ordinary skill in theart in view of the teachings herein. In some instances, only innerdiameter (218) or outer dimeter (216) is radiused, while the othersimply connects to the respective curved surface (206, 208).

It may be desirable to ensure device (20), or any suitable devicementioned herein, generates a cumulative constrictive pressure that canprevent gastric fluid from passing the LES (6). The resulting magneticfield flux density necessary to create 15 mm/Gg-25 mm/Hg of pressurebetween a bead (30, 150) and exterior of esophagus (2) is 0.4-0.6 teslaat the focal point and diminishes to 0.2-/0.1 tesla as you move awayfrom the focal point. This would provide a function range of magneticflux density of 0.05-0.8 tesla with the ideal magnetic flux density inthe range of 0.2-0.6 tesla in the constricted configuration.

As mentioned above, it may be desirable to “tune” a magnet (60, 100,160, 200, 240) such that the generated magnetic fields are aligned withresting contact surfaces (158) of beads (150) in the contracted state.Therefore, in some instances, it may be desirable to provide a surfacecontact area that is aligned to the interfacing features betweenadjacent beads (150) in a contracted state. FIGS. 21-22 show analternative bead (300) that may be readily incorporated into device (20)in replacement of beads (30, 150) described above. Beads (300) may besubstantially similar to beads (30, 150) described above, withdifferences described below. Therefore, each bead (300) may house atleast one magnet (60, 100, 160, 200, 240). Additionally, each bead (300)defines a chamber (306) and include a first housing (302) defining anopening (303), and a second housing (304) defining an opening (305);which may be substantially similar to chamber (36), housing (32)defining opening (33), and housing (34) defining opening (35) describedabove respectively. Therefore, chamber (36) may slidingly house aportion of link (40) such that link (40) may connect adjacent beads(300).

Additionally, each bead (300) has a pair of substantially flat contactsurfaces (308). Contact surfaces (308) are enlarged and configured toabut against directly adjacent contact surfaces (308) when device (20)opens in the contracted configuration. The large flat contact surface(308) may provide a larger plane of alignment to allow magnetic fields(118, 188, 228, 268) to more easily align relative to adjacent beads(300), thereby providing more control and stability. It may be desirableto align the center of magnetic fields (118, 188, 228, 268) with thecenter of the contact surface (308). In the current example, contactsurfaces (308) extend along a plane that goes through a central point ofdevice (20). However, this is merely optional, as contact surfaces (308)may extend along any suitable plane as would be apparent to one havingordinary skill in the art in view of the teachings herein. Contactsurfaces (308) may terminate a suitable distance from the inner diameterportion of bead (300) such that contact surfaces (308) may be lesslikely to pinch or otherwise harm tissue which device (20) surrounds.Contact surfaces (308) may have any suitable complementary geometry topromote locking between beads (300) when device is in a contractedstate. For instance, contact surface (308) may have complementaryundulating ribs configured to lock against adjacent contact surfaces(308) in the contracted state, thereby promoting stability.

B. Magnetic Features to Promote Variable Magnetic Field Strengths withinSphincter Augmentation Devices

In some instances, it may be desirable to “tune” a magnetic field withindevice (20) by controlling and varying the magnetic field strengthwithin different beads (30, 150, 300). Controlling and varying themagnetic field strengths within different beads (30, 150, 300) may allowfor better control of the profile of device (20) in the contractedstate. In some instances, is may be desirable to allow a magnet (60,100, 160, 200, 240) to float within a respective magnetic chamber ofbead (30, 150, 300) so that the magnetic field generated by adjacentbeads (30, 150, 300) is stronger with one adjacent bead (30, 150, 300)compared to the other adjacent bead (30, 150, 300). Additionally, it maybe advantageous to magnetize link (40) such that link (40) may encouragemagnets (60, 100, 160, 200, 240) to float to a predetermined side of amagnetic chamber, thereby controlling which adjacent bead (30, 150, 300)has a stronger magnetic field compared to the other adjacent bead (30,150, 300). In other instances, it may be desirable to use a magnet (60,100) of different magnetic strength in various beads (30, 150, 300) inorder to control and vary the magnetic fields generated by device (20).

FIG. 23 shows a plurality of alternative beads (310), where each bead(310) houses one magnet (100), that may be readily incorporated intodevice (20) described above. While one magnet (100) is housed withineach bead (310), it should be understood a plurality of magnets (100)may be “stacked” together and housed within a single bead (310). Anysuitable number of magnets (100) used in a single bead (310) will beapparent to one having ordinary skill in the art in view of theteachings herein. Beads (310) may be substantially similar to beads (30,150, 300) described above, with differences elaborated below. Therefore,adjacent beads (310) may be connected by links (40) such that beads(310) may expand and contract between a contracted configuration and anexpanded configuration while magnets (100) magnetically bias theplurality of beads (310) toward the contracted configuration.

Each bead (310) defines a magnetic chamber (312) dimensioned to slidablyhouse magnet (100) such that magnet (100) may translate, slide, orotherwise “float” toward and away adjacent beads (310). Because magnet(100) may translate toward and away from adjacent beads (310), amagnetic field (318) generated by adjacent beads (310) is stronger thana magnetic field (315) generated by the opposite adjacent bead (310). Inparticular, magnetic chamber (312) extends along a chamber length (314)that spans toward adjacent beads (310). Chamber length (314) is longerthan the length of magnet (100). Magnetic chamber (312) is furtherdimensioned to slidably house magnet (100) such that magnet (100) maytranslate along a path defined by chamber length (314).

Since magnet (100) is slidably housed within magnetic chamber (312),magnet (100) may slide closer to one adjacent bead (310), therebydefining a gap (316) within magnetic chamber (312). Magnetic field (315)generated by the sides of adjacent magnets (100) defining gap (316) isweaker than magnetic field (318) generated by sides of adjacent magnets(100) not defining gap (316). This is due in part to the fact theportions of adjacent magnets (100) generating the stronger magneticfield (318) are closed to each other than the portions of adjacentmagnets (100) generating the weaker magnetic field (315). Magnets (100)may slide within magnetic chamber (312) along the path defined bychamber length (314) to different positions within magnetic chamber(312) as beads (310) transition between the contracted state and theexpanded state such that the strength of magnetic fields (318, 315)compared to each other may change as beads (310) expand and contract. Inother examples, magnets (100) may be fixed within beads (310), butoffset along the path defined by chamber length (314) such that onemagnetic field (318) is always stronger than the other magnetic field(315).

In some instances where magnet (100) is slidably housed within magneticchamber (312), it may be desirable to encourage magnet (100) totranslate to a predetermined side of magnetic chamber (312), therebycontrolling which adjacent bead (310) has the stronger magnetic field(318) and which adjacent bead (310) has the weaker field (315). FIGS.24-25 show an exemplary pair of beads (320) coupled by a magnetic link(322) that may be readily incorporated into device (20) described above.Beads (320) are substantially similar to beads (310) described above.Therefore, beads (320) house magnets (100) such that magnets (100) mayslide within beads (320) toward and away from adjacent beads (320).Magnetic link (322) is slidably attached to adjacent beads (320) suchthat adjacent beads (320) may transition between the contracted state(as shown in FIG. 24) and the expanded state (as shown in FIG. 25).Magnetic link (322) includes a north pole section (324) terminating intoa ball tip and a south pole section (326) terminating into a ball tip.Ball tip of north pole section (324) is slidably contained within thefirst magnetic bead (320) while ball tip of south pole section (326) isslidably contained within second magnetic bead (320).

As best seen in FIG. 24, when beads (320) are in the contracted state,ball tip of north pole section (324) is adjacent to south pole section(112) of magnet (100) within the first bead (320) (on the left); whileball tip of south pole section (326) is adjacent to north pole section(110) of magnet (100) within second bead (320) (on the right).Therefore, the magnetic attraction between ball tip of north polesection (324) and south pole section (112) of the magnet (100) withinfirst bead (320) (on the left) may pull magnet (100) within first bead(320) toward second bead (320) (on the right). Similarly, the magneticattraction between ball tip of south pole section (326) and north polesection (110) of magnet (100) within second bead (320) (on the right)may pull magnet (100) within second bead (320) toward first bead (320)(on the left). As such, magnetized link (322) may help encourage magnets(100) within adjacent beads (320) to translate toward each other in thecontracted position. Of course, magnetized link (322) may be attached tobeads (320) in the reversed order such that magnetized link (322) mayhelp encourage magnets (100) within adjacent beads (320) to translateaway from each other in the contracted position.

As best seen in FIG. 25 when beads (320) are in the expanded state, balltip of north pole section (324) is adjacent to north pole section (110)of magnet (100) within the first bead (320) (on the left); while balltip of south pole section (326) is adjacent to south pole section (112)of magnet (100) within second bead (320) (one the right). Therefore, themagnetic repulsion between ball tip of north pole section (324) andnorth pole section (110) of the magnet (100) within first bead (320) (onthe left) may push magnet (100) within first bead (320) away from secondbead (320) (on the right). Similarly, the magnetic repulsion betweenball tip of south pole section (326) and south pole section (112) ofmagnet (100) within second bead (320) (on the right) may pull magnet(100) within second bead (320) away from first bead (320) (on the left).As such, magnetized link (322) may help encourage magnets (100) withinadjacent beads (320) to translate away from one other in the contractedposition. Of course, magnetized link (322) may be attached to beads(320) in the reversed order such that magnetized link (322) may helpencourage magnets (100) within adjacent beads (320) to translate towardeach other in the expanded position.

In the current examples, each bead (320) contains a magnetized link(322) and a non-magnetized link (328) such that links (322, 328) extendaround device (20) in an alternating fashion, however this is merelyoptional. Any suitable arrangement of magnetized links (322) andnon-magnetized links (328) may be used as would be apparent to onehaving ordinary skill in the art in view of the teachings herein. Insome instances, only magnetized links (322) may be used. In someinstances, a variety of magnetized links (322) may be used havingdifferent magnetic strengths. As would be apparent to one havingordinary skill in the art in view of the teachings herein, any suitablearrangement of magnetized links (322) and non-magnetized links (328) maybe used to encourage a desired shape of device (20) in the contractedstate, in the expanded state, or any position in-between.

FIGS. 26-28 show an alternative sphincter augmentation device (330) thatmay be used in replacement of device (20) described above. Device (330)is substantially similar to device (20) described above, withdifferences elaborated below. Device (330) includes magnetic beads (336,338), which may be substantially similar to beads (30) and correspondingmagnetics (60) described above. Therefore, adjacent beads (336, 338) ofdevice (330) are slidable connected by links (340). Links (340) may besubstantially similar to links (40, 322, 328) described above. Beads(336, 338) may expand and contract relative to each other between acontracted state and an expanded state in similar fashion to device (20)described above while being magnetically biased to the contracted state,with differences described below.

In particular, device (330) includes two clusters of stronger magneticbeads (332) and two clusters of weaker magnetic beads (334). Clusters ofmagnetic beads (332, 334) are arranged to generate magnetic fields (342,344, 346) of varying strengths such that device (330) forms an elongatedoval shape in the contracted state (as shown in FIG. 26). While clustersof magnetic beads (332, 334) are arranged to form an oval shape in thecurrent example, this is merely exemplary, as clusters of magnetic beads(332, 334) may be arranged to generate magnetic field (342, 344, 346) ofvarying strengths to form any suitable shape as would be apparent to onehaving ordinary skill in the art in view of the teachings herein.

Clusters of stronger magnetic beads (332) include an array of individualstrong magnetic beads (336) coupled by links (340); while clusters ofweaker magnetic beads (334) include an array of individual weakermagnetic beads (338) coupled by links (340). Stronger magnetic beads(336) include magnets with a strong magnetic flux; while weaker magneticbeads (338) include magnets with a relatively weaker magnetic flux.Therefore, magnetic fields (342) generated between adjacent weakermagnetic beads (338) are weaker relative to magnetic fields (344)generated between adjacent stronger magnetic beads (336). Additionally,magnetic fields (346) generated between stronger magnetic beads (336)and adjacent weaker magnetic beads (338) will be valued somewherebetween strong magnetic field (346) and weaker magnetic field (344).

FIG. 26 shows device (330) in a contracted state under a first radiallyoutward pressure (P1) imparted on device (330) from expansion of LES(6). For exemplary purposes only, first radially outward pressure (P1)may be between 0.00 mm/Hg and 25 mm/Hg. As shown in FIG. 27, since weakmagnetic beads (338) are attracted to each other via a weak magneticfield (342) as compared to stronger magnetic field (344) andintermediary magnetic field (346), weak magnetic beads (338) may beginto expand relative to each other under a second radial outward force(P2) from expansion LES (6), prior to stronger magnetic beads (336)expanding relative to each other. For exemplary purposes only, secondradially outward pressure (P2) may be around values beginning to exceed35 mm/Hg. Therefore, under second radial outward force (P2), device(330) may expand to an intermediary expanded state, as shown in FIG. 27.FIG. 28 shows device (330) in a fully expanded state where weak magneticbeads (338) and strong magnetic beads (336) are expanded relative toeach other under a third radially outward force (P3) from expansion ofLES (6). For exemplary purposes only, third radially outward force (P3)may be around 80 mm/Hg. Therefore, device (330) may maintain anelongated oval shape over a first range of radially outward pressuresprovided by expansion of LES (6), then device (330) may expand into asecond, circular, shape in response to a larger radially outwardpressure provided by expansion of LES (6). Allowing different shapes ofdevice (330) in the contracted and partially expanded shape may allowfor device (330) to better encompass the targeted sphincter, such as LES(6), an anal sphincter, or any other suitable sphincter as would beapparent to one having ordinary skill in the art in view of theteachings herein.

In some instances, it may be desirable to use different thickness ofmagnets in magnetic beads (336, 338). This may enable the tuning of boththe overall diameter of device (330) in smaller selectable increments,as well as the ability to tube the magnetic field strength by controlthe distance and mass of the magnet in a more incremental manner,thereby lowering the overall compressive force for the same size of beadgeometry.

When device (330) increases in perimeter, a mixture of magnet sizeswithin beads (336, 338) could be swapped out in order to create largermagnetic attraction for the larger device (330), since the beads (336,338) are capable of being farther apart in the fully expanded state thanbeads (336, 338) in the smaller diameter implant could be.

C. Magnetic Features to Promote Angular Alignment Between Adjacent Beads

As mentioned above adjacent beads (30, 150, 300, 310, 320, 336, 338) maybe magnetically biased toward each other such that device (20, 330) isbiased toward the contracted state (as shown in FIGS. 3, 5B, and 26). Inparticular, the magnetic bias of adjacent beads (30, 150, 300, 310, 320,336, 338) is due, at least in part, to the north-south pole alignment ofmagnets (60, 100, 160, 200, 240) in adjacent beads (30, 150, 300, 310,320, 336, 338). However, as exemplified in magnet (100), since northpole sections (110) and south pole sections (112) of magnet (100) coverthe entirety of annular axially presented surfaces (102, 104), adjacentbeads (30, 150, 300, 310, 320, 336, 338) may be magnetically attractedto each other, regardless of the rotational position of bead (30, 150,300, 310, 320, 336, 338) about link (40, 322, 328, 340) relative to anadjacent bead (30, 150, 300, 310, 320, 336, 338). This may causedifficulties to suitably align beads (30, 150, 300, 310, 320, 336, 338)during assembly or to maintain alignment during exemplary use.

In some instances, bead (30, 150, 300, 310, 320, 336, 338) may have aresting contact surface configured to abut against the resting contactsurface of a directly adjacent bead (30, 150, 300, 310, 320, 336, 338).If bead (30, 150, 300, 310, 320, 336, 338) is rotated about link (40,322, 328, 340) relative to adjacent beads (30, 150, 300, 310, 320, 336,338) such that resting contact surfaces are not suitably aligned,resting contact surfaces may not make contact with each other whendevice (20, 330) is in the contracted state, which may cause undesirableconsequences. Therefore, it may be desirable to magnetically “tune”device (20, 330) to ensure that adjacent beads (30, 150, 300, 310, 320,336, 338) are magnetically biased to the contracted state and are alsomagnetically biased to be rotationally aligned with each other aboutlink (40, 322, 328, 340) (i.e. “clocked”).

FIG. 29 shows alternative beads (350), link (354), and magnet assemblies(360) that may be readily incorporated into device (20, 330) describedabove. Beads (350) may be substantially similar to bead (30, 150, 300,310, 320, 336, 338) described above, with differences elaborated below.Beads (350) include a housing assembly (356) that houses a respectivemagnetic assembly (360) and a portion of associated links (354).Therefore, adjacent beads (350) may be connected by links (354) suchthat beads (350) may expand and contract between a contractedconfiguration and an expanded configuration while respective magnetassemblies (360) magnetically bias the plurality of beads (350) towardthe contracted configuration. Beads (350) include resting contactsurfaces (352) configured to abut against each other in the contractedconfiguration. As will be described in greater detail below, magnetassemblies (360) are configured to generate magnetic fields withadjacent magnet assemblies (360) to magnetically bias correspondingbeads (350) to a predetermined, “clocked,” rotational position aboutlink (354) relative to each other.

Magnetic assemblies (360) extend between a first annular axiallypresented surface (362) and a second annular axially presented surface(364). Unlike magnet (100) described above, axially presented surfaces(362, 364) are not uniformly north pole sections and south polesections. Instead, magnetic assemblies (360) include axially extendingnorth pole sectors (366) and axially extending south pole sectors (368)that span between first annular axially presented surface (362) andsecond annular axially presented surface (364). Each individual northpole sector (366) associates with a corresponding individual south polesector (368). In the current example, there are two north pole sectors(366) and two south pole sectors (368), where each sector spans about aquarter of each axially presented surface (362, 364). Also in thecurrent example, sectors (366, 368) are arranged annularly in analternating fashion such that each north pole sector (366) in anindividual magnetic assembly (360) is adjacent to a south pole sector(368) within the same individual magnetic assembly (360). As will bedescribed in greater detail below, any suitable number of sectors (366,368) may be used in any suitable annular arrangement as would beapparent to one having ordinary skill in the art.

Individual north pole sectors (366) and individual south pole sectors(368) may be attached to each other/magnetized through any suitablemeans as would be apparent to one having ordinary skill in the art inview of teachings herein. When assembled, magnetic assemblies (360) arerotationally retained within respective housing assembly (356) such thatmagnetic assemblies (360) may not rotate relative to housing assembly(356) about an axis extending between annular axially presented surfaces(362, 364).

Magnetic assemblies (360) within adjacent beads (350) are polar mirrorsof each other. In other word, magnetic assemblies (360) are positionedwithin beads (350) such that when assembled, a north pole sector (366)within a first bead (350) is adjacent to a south pole sector (368) of asecond, adjacent bead (350). This alignment promotes a magnetic bias ofbeads (350) toward the contracted configuration in accordance with thedescription above. Additionally, with north pole sectors (366) and southpole sectors (368) extending between both annular axially presentedsurfaces (362, 364), north pole sectors (366) of a first bead (350) maybe magnetically repelled by north pole sectors (366) of a second bead(350) when beads (350) are in the contacted configuration. Due to themirrored polarity of adjacent magnetic assemblies (360), along with theaxially extending north and south polar sectors (366, 368), thismagnetic repulsion helps encourage angular alignment (i.e. clocking)between adjacent beads (350) about link (354) relative to each other.Therefore, magnetic assemblies may help adjacent beads (350) formangular alignment during assembly or maintain angular alignment duringexemplary use.

FIG. 30 shows beads (350) and link (354) with alternative magnetassemblies (370) incorporated therein. Therefore, adjacent beads (350)may be connected by links (354) such that beads (350) may expand andcontract between a contracted configuration and an expandedconfiguration while respective magnet assemblies (370) magnetically biasthe plurality of beads (350) toward the contracted configuration. Aswill be described in greater detail below, magnet assemblies (370) areconfigured to generate magnetic fields with adjacent magnet assemblies(370) to magnetically bias corresponding beads (350) to a predetermined,“clocked,” rotational position about link (354) relative to each other.

Magnetic assemblies (370) extend between a first annular axiallypresented surface (372) and a second annular axially presented surface(374). Unlike magnet (100) described above, axially presented surfaces(372, 374) are not uniformly north pole sections and south polesections. Instead, magnetic assemblies (370) include axially extendingnorth pole sectors (376) and axially extending south pole sectors (378)that span between first annular axially presented surface (372) andsecond annular axially presented surface (374). Each individual northpole sector (376) associates with a corresponding individual south polesector (378). In the current example, there are five north pole sectors(376) and five south pole sectors (378), where each sector spans about afifth of each axially presented surface (372, 374). Also in the currentexample, sectors (376, 378) are arranged annularly in a fashion suchthat some north pole sectors (376) in an individual magnetic assembly(370) are adjacent only to south pole sector (378) within the sameindividual magnetic assembly (370); while some north pole sectors (376)in individual magnetic assembly (370) are adjacent to another north polesector (376) and a south pole sector (378). Any suitable number ofsectors (376, 378) may be used in any suitable annular arrangement aswould be apparent to one having ordinary skill in the art.

Individual north pole sectors (376) and individual south pole sectors(378) may be attached to each other/magnetized through any suitablemeans as would be apparent to one having ordinary skill in the art inview of teachings herein. When assembled, magnetic assemblies (370) arerotationally retained within respective housing assembly (356) such thatmagnetic assemblies (370) may not rotate relative to housing assembly(356) about an axis extending between annular axially presented surfaces(362, 364).

Magnetic assemblies (370) within adjacent beads (350) are polar mirrorsof each other. In other word, magnetic assemblies (370) are positionedwithin beads (350) such that when assembled, a north pole sector (376)within a first bead (350) is adjacent to a south pole sector (378) of asecond, adjacent bead (350). This alignment promotes a magnetic bias ofbeads (350) toward the contracted configuration in accordance with thedescription above. Additionally, with north pole sectors (376) and southpole sectors (378) extending between both annular axially presentedsurfaces (372, 374), north pole sectors (376) of a first bead (350) maybe magnetically repelled by north pole sectors (376) of a second bead(350) when beads (350) are in the contacted configuration. Due to themirrored polarity of adjacent magnetic assemblies (370), along with theaxially extending north and south polar sectors (376, 378), thismagnetic repulsion helps encourage angular alignment (i.e. clocking)between adjacent beads (350) about link (354) relative to each other.Therefore, magnetic assemblies may help adjacent beads (350) formangular alignment during assembly or maintain angular alignment duringexemplary use.

While in the current examples, magnetic assemblies (360, 370) includenorth pole sectors (366, 376) and south pole sectors (368, 378), anysuitable geometry may be used as would be apparent to one havingordinary skill in the art in view of the teachings herein. For example,FIG. 31 show an alternative magnetic assembly (380) including axiallyextending north pole rods (386) with corresponding axially extendingsouth pole rods (388). Magnetic assembly (380) may be substantiallysimilar to magnetic assembly (360, 370) described above, except theshape of north and south pole components are rods. While rods (386, 388)are used as an alternative example, any other suitable geometry may beincorporated as would be apparent to one having ordinary skill in theart in view of the teachings herein.

In addition to providing advantages by rotationally clocking beads(350), magnetic assemblies (360, 370, 380) having numerous north andsouth poles on each side of the magnetic assembly may provide advantageswhen exposed to an external magnetic field. For example, as shown inFIG. 32, when a device (20) composed of beads (350) with magneticassemblies (380) is exposed to a uniform MRI field (170). Magneticassemblies (380) ability to resist twisting relative to each other dueto the arrangement of north pole rods (386) and south pole rods (388).Therefore, magnetic assemblies (380) may prevent uniform MRI field (170)from overtly distorting the target contracted state shape (80) of beads(350), as compared to if device (20) is exposed to uniform MRI field(170), as shown in FIG. 33.

D. Tissue Compression Limits to Minimize Inadvertent Tissue Damage whileMaintaining Sphincter Control

It may be desirable to have device (20, 330) or any variation of device(20, 330) described herein has operational compression limits whichdevice (20, 330) may impart onto tissue creating a sphincter, such asLES (6). It may be desirable to have compression limits between apressure range having a lower limit such that device (20, 330) mayfunction as a sphincter reinforcement device, but with an upper limitwhere device (20, 330) does not damage tissue. For esophagealreinforcement, this pressure range may be above the gastric pressure,subtracting what the sphincter can still exert, but less than thepressure that induces discomfort or inhibits swallowing. A rectalsphincter will have similar requirements with different pressures forsignificantly different reasons. Some ways to control these compressionlimits is for beads (30) to have predefined contacts in the contractsstate to limit long term tissue compression under a predefinedthreshold. Another way is to have increased internal diameter surfacearea contact between device (20) and the tissue being restricted.

III. Exemplary Combinations

The following examples relate to various non-exhaustive ways in whichthe teachings herein may be combined or applied. It should be understoodthat the following examples are not intended to restrict the coverage ofany claims that may be presented at any time in this application or insubsequent filings of this application. No disclaimer is intended. Thefollowing examples are being provided for nothing more than merelyillustrative purposes. It is contemplated that the various teachingsherein may be arranged and applied in numerous other ways. It is alsocontemplated that some variations may omit certain features referred toin the below examples. Therefore, none of the aspects or featuresreferred to below should be deemed critical unless otherwise explicitlyindicated as such at a later date by the inventors or by a successor ininterest to the inventors. If any claims are presented in thisapplication or in subsequent filings related to this application thatinclude additional features beyond those referred to below, thoseadditional features shall not be presumed to have been added for anyreason relating to patentability.

Example 1

An implantable restriction device, the implantable restriction devicecomprising: (a) a plurality of beads, wherein each bead comprises: (i) ahousing comprising a contact surface, (ii) a passageway extendingthrough the housing, wherein the passageway defines an axis, and (iii)at least one magnet disposed around the passageway; and (b) a pluralityof links joining the beads together, wherein portions of the links areslidably disposed in corresponding passageways of the beads such thatthe plurality of beads are operable to transition between an constrictedconfiguration and an expanded configuration, wherein contact surfaces ofadjacent beads in the plurality of beads are configured to abut againsteach other in the constricted configuration, wherein the at least onemagnet of adjacent beads in the plurality of beads generate aninteractive magnetic field focused on the abutting contact surfaces ofadjacent beads in the plurality of beads.

Example 2

The implantable restriction device of Example 1, wherein the at least onmagnet comprises at least one annular magnet.

Example 3

The implantable restriction device of Example 2, wherein the at leastone annular magnet in at least one bead of the plurality of beadscomprises a chamfered corner.

Example 4

The implantable restriction device of Example 3, wherein the at leastone annular magnet comprises an outer diameter, wherein the chamferedcorner is located on the outer diameter.

Example 5

The implantable restriction device of any one or more of Examples 2through 4, wherein the at least one annular magnet in at least one beadof the plurality of beads comprises a radiused corner.

Example 6

The implantable restriction device of Example 5, wherein the at leastone annular magnet comprises an inner diameter, wherein the radiusedcorner is located on the inner diameter.

Example 7

The implantable restriction device of any one or more of Examples 1through 6, wherein the contact surface comprises a flat surface.

Example 8

The implantable restriction device of Example 7, wherein the flatsurface extends along a plane that intersects with a center point of theimplantable restriction device.

Example 9

The implantable restriction device of any one or more of Examples 1through 8, wherein the housing defines a magnet chamber configured tohouse the at least one magnet.

Example 10

The implantable restriction device of Example 9, where the at least onemagnet extends along a first length, wherein the magnet chamber extendsalong a second length.

Example 11

The implantable restriction device of any one or more of Examples 9through 10, wherein the second length is longer than the first lengthsuch that the at least one magnet is configured to translate within themagnet chamber.

Example 12

The implantable restriction device of Example 11, wherein at least onelink in the plurality of links in magnetized.

Example 13

The implantable restriction device of Example 12, wherein the at leastone link is configured to pull the at least one magnet of adjacent beadstoward each other in the contracted configuration.

Example 14

The implantable restriction device of any one or more of Examples 12through 13, wherein the at least one link is configured to push the atleast one magnet of adjacent beads away from each other in thecontracted configuration.

Example 15

The implantable restriction device of any one or more of Examples 1through 14, wherein the plurality of beads comprises a first group ofbeads and a second group of beads, wherein the at least one magnet inthe first group of beads comprises a first magnetic flux density,wherein the at least one magnet in the second group of beads comprises asecond magnetic flux density.

Example 16

The implantable restriction device of Example 15, wherein the firstmagnetic flux density is greater than he second magnetic flux density.

Example 17

An implantable restriction device, the implantable restriction devicecomprising: (a) at least two beads, wherein each bead comprises: (i) ahousing comprising a contact surface, (ii) a passageway extendingthrough the housing, wherein the passageway defines an axis, and (iii)at least one magnet disposed around the passageway; and (b) at least onelink joining the beads together, wherein portions of the links areslidably disposed in corresponding passageways of the beads such thatthe at least two beads are operable to transition between an constrictedconfiguration and an expanded configuration, wherein contact surfaces ofadjacent beads in the at least two beads are configured to abut againsteach other in the constricted configuration, wherein the at least onemagnet of adjacent beads in the plurality of beads is configured togenerate an interactive magnetic field extending along a field focusedaxis that intersects through abutting contact surfaces of adjacent beadsin the at least two beads in the constricted configuration.

Example 18

An implantable restriction device, the implantable restriction devicecomprising:(a) a series of beads interconnected to form a ring, whereinthe ring is configured to transition between a contracted configurationand an expanded configuration; and(b) at least one ring-shaped magnetcontained within each bead in the series of beads, wherein the at leastone ring-shaped magnet of a first bead in the series of beads isconfigured to generate a first magnetic field, wherein the at least onering-shaped magnet of a second bead in the series of beads is configuredto generate a second magnetic field, where the first bead and the secondbead are adjacent to each other, wherein the first magnetic field andthe second magnetic field are focused at substantially a predeterminedcontact point between the first bead and the second bead.

Example 19

The implantable restriction device of Example 18, wherein the firstmagnet field and the second magnetic field are most intense at thepredetermined contact point.

Example 20

The implantable restriction device of any one or more of Examples 18through 19, wherein the series of beads comprise a non-ferrous material.

IV. Miscellaneous

It should also be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

1-20. (canceled)
 21. An implantable restriction device, the implantable restriction device comprising: (a) a plurality of beads, wherein each bead comprises: (i) a housing comprising a contact surface, (ii) a passageway extending through the housing, wherein the passageway defines an axis, and (iii) at least one magnet disposed around the passageway, wherein the at least one magnet comprises at least one annular magnet, wherein the at least one annular magnet in at least one bead of the plurality of beads comprises: (A) an outer diameter that includes at least one chamfered corner or radiused corner, and (B) an inner diameter that includes at least one chamfered corner or radiused corner; and (b) a plurality of links joining the beads together, wherein portions of the links are slidably disposed in corresponding passageways of the beads such that the plurality of beads are operable to transition between an contracted configuration and an expanded configuration, wherein the contact surfaces of adjacent beads in the plurality of beads are configured to abut against each other in the contracted configuration, wherein the at least one magnet of adjacent beads of the plurality of beads generates an interactive magnetic field extending along a field focused axis that intersects through the abutting contact surfaces of adjacent beads of the plurality of beads in the contracted configuration.
 22. The implantable restriction device of claim 21, wherein the outer diameter includes the first and second radiused corners.
 23. The implantable restriction device of claim 21, wherein the inner diameter includes the first and second radiused corners.
 24. The implantable restriction device of claim 21, wherein the contact surface includes a planar surface.
 25. The implantable restriction device of claim 21, wherein each bead of the plurality of beads includes a pair of contact surfaces configured to abut against contact surfaces of the adjacent beads in the contracted configuration.
 26. The implantable restriction device of claim 21, wherein the housing defines a magnet chamber configured to house the at least one magnet.
 27. The implantable restriction device of claim 21, wherein the magnets are configured to direct respective magnetic fields into suitable alignment with the contact surfaces of the beads.
 28. The implantable restriction device of claim 21, wherein the at least one radiused corner of the inner diameter has a dimension of approximately 0.005 inches.
 29. The implantable restriction device of claim 21, wherein the at least one chamfered corner of the outer diameter has a dimension of approximately of 0.015 inches.
 30. The implantable restriction device of claim 21, wherein the magnet includes first and second axially presented surfaces that in combination with the chamfered corner of the outer diameter and the radiused corner of the inner diameter are dimensioned to create a magnetic field having a stronger portion, an intermediary portion, and a weaker portion.
 31. An implantable restriction device, the implantable restriction device comprising: (a) a plurality of beads, wherein each bead comprises: (i) a housing comprising a contact surface, (ii) a passageway extending through the housing, wherein the passageway defines an axis, and (iii) at least one magnet disposed around the passageway, wherein the at least one magnet comprises at least one annular magnet, wherein the at least one annular magnet in at least one bead of the plurality of beads comprises: (A) a radiused inner diameter, and (B) a radiused outer diameter; and (b) a plurality of links joining the beads together, wherein portions of the links are slidably disposed in corresponding passageways of the beads such that the plurality of beads are operable to transition between an contracted configuration and an expanded configuration, wherein contact surfaces of adjacent beads in the plurality of beads are configured to abut against each other in the contracted configuration and be separated from each other in the expanded configuration, wherein the at least one magnet of adjacent beads of the plurality of beads generates an interactive magnetic field focused on the abutting contact surfaces of adjacent beads of the plurality of beads.
 32. The implantable restriction device of claim 31, wherein the at least one magnet includes first and second axially presented surfaces, wherein the geometry of the first and second axially presented surfaces in combination with the radiused outer diameter and the radiused inner diameter are configured to generate sections of magnetic fields that are aligned with the contact surface to promote the beads to impart forces on a lower esophageal sphincter of a patient due to magnetic attraction between the adjacent beads while the implantable restriction device is in the contracted configuration and the expanded configuration.
 33. The implantable restriction device of claim 31, wherein the at least one magnet includes a first axially presented surface, a second axially presented surface, an outer facing curved surface, and an inner facing curved surface, wherein the first and second axially presented surfaces in combination with the radiused outer diameter and the radiused inner diameter are configured to create a magnetic field having a stronger portion, an intermediary portion, and a weaker portion.
 34. The implantable restriction device of claim 33, wherein the geometry of the first and second axially presented surfaces in combination with radiused outer diameter and the radiused inner diameter is configured to generate sections of the magnetic field that are aligned with contact surfaces to promote stability between adjacent beads in the contracted configuration.
 35. The implantable restriction device of claim 31, wherein the at least one magnet includes a first axially presented surface, a second axially presented surface, an outer facing curved surface, and an inner facing curved surface, wherein the radiused outer diameter connects the first and second axially presented surfaces with the outer facing curved surface, wherein the radiused inner diameter connects the first and second axially presented surfaces with the inner facing curved surface.
 36. The implantable restriction device of claim 31, wherein at least one of the radiused outer diameter or the radiused inner diameter has a dimension of approximately 0.005 inches. (a) a series of beads interconnected to form a ring, wherein the ring is configured to transition between a contracted configuration and an expanded configuration; and (b) at least one annular magnet contained within each bead in the series of beads, wherein the at least one annular magnet comprises: (i) a first axially presented surface, (ii) a second axially presented surface disposed opposite the first axially presented surface, (iii) a radiused inner diameter, and (iv) a radiused outer diameter, wherein the geometry of the first and second axially presented surfaces in combination with the radiused outer diameter and radiused inner diameter is configured to generate sections of a magnetic field that are aligned with contact surfaces to promote stability between adjacent beads in the contracted configuration.
 38. The implantable restriction device of claim 37, wherein the geometry of the first and second axially presented surfaces in combination with the radiused outer diameter and radiused inner diameter are configured to generate sections of magnetic fields that are aligned with the contact surface to promote beads to impart forces on a lower esophageal sphincter of a patient due to the magnetic attraction between the adjacent beads while the implantable restriction device is in the contracted configuration and the expanded configuration.
 39. The implantable restriction device of claim 37, wherein the at least one annular magnet of a first bead in the series of beads is configured to generate a first magnetic field, wherein the at least one annular magnet of a second bead in the series of beads is configured to generate a second magnetic field, where the first bead and the second bead are adjacent to each other, wherein the first magnetic field and the second magnetic field are focused substantially at a predetermined contact point between the first bead and the second bead.
 40. The implantable restriction device of claim 39, wherein the first magnetic field and the second magnetic field are most intense at the predetermined contact point such that the focused direction of the magnetic field relative to the contact surfaces is configured to improve stability between adjacent beads in the contracted configuration. 